The invention relates to a mixing container with a top filling opening, with a connection flange which projects outward in the area of the top filling opening in a radial direction for connecting the mixing container to the mixing head of an industrial mixing machine and with a bottom discharge that can be blocked and opened. Furthermore, the invention relates to an emptying station for such a mixing container.
Mixing containers of this type are connected to a mixing machine for mixing material to be mixed this container. Such mixing machines are industrial mixers which are used for mixing bulk material in particular, typically powdery bulk material such as for preparing mixtures of plastic granulate or in the color industry. These mixing machines comprise a mixing head pivotably supported opposite a frame. The mixing head also serves to simultaneously close a mixing container which is connected to the mixing head for mixing the material. After the mixing container has been connected to the mixing head a closed receptacle is formed by the mixing head and the container containing the material to be mixed. For connecting the mixing container to the mixing head the mixing head comprises one or more connecting elements, for example a circumferential flange as support surface for a complementary connection flange of the mixing container and comprises locking members for locking the mixing container on the mixing head. Due to the fact that in these mixing machines have a mixing container connected to the mixing head these mixers are also known as container mixers. The mixing head itself is pivotably arranged opposite the machine frame of the mixing machine such that the mixing takes place relative to the mixing head in an upside down position in which the mixing head is at the bottom and the mixing container connected to it is arranged at the top. In this position the bottom discharge opening of the mixing container faces upward.
This upside down position is required so that the material to be mixed comes in contact with the at least one mixing tool carried by the mixing head. The rotationally driven mixing tool serves to generate a flow of material to be mixed inside the closed mixing chamber. The time of the mixing procedure determines the degree of mixing. Such an industrial mixer is known, for example, from EP 0 225 495 A2.
Mixing containers of the previously described type are manufactured from stainless steel in order that they satisfy the requirements placed on the container. The filling opening of the mixing container is formed by the upper closure of an annular, cylindrical wall. A truncated cone section constructed as a ring borders this wall in the direction of the discharge by which the inside diameter of the container tapers from a cylindrical diameter to the diameter of the discharge. A blocking flap is built into the discharge, which is typically constructed as a discharge conduit, for opening and closing it. This flap can generally be manually activated from the outside by a lever. Once the material is mixed, the mixing container is moved with the mixed mixing material to an emptying station. In this station the discharge is connected to the inlet of the next processing station. Then the blocking flap is opened so that the pourable mixed material contained in the mixing container can flow out of it, emptying the mixing container. The emptying of such a mixing container takes place as a function of the processing station connected in downstream in one batch or in several smaller batches. In the latter instance the mixing container also serves as a storage container.
When emptying pourable mixing material bridges of mixing material can form in the conically tapered section. In such an instance only the mixing material located below such a mixing material bridge can flow out of the mixing container without additional measures. Such mixing material bridges are produced by compaction of the mixing material located in the mixing container by reduction of the pore volume, typically as a process of material being set in the area of the tapered container section, favored by the weight of the mixing material located above it. In order to avoid the formation of such mixing material bridges or also to destroy present mixing material bridges to ensure a complete emptying of the mixing container, a vibration motor or a knocking generator is connected into the emptying station on the outer wall of the mixing container. As a result of the oscillations introduced into the container wall in this manner the mixing material contained in the mixing container during the process of emptying is put or held in motion and therefore fluidized to a certain extent, which counteracts a production of mixing material bridges during the emptying. Such a measure can destroy produced mixing material bridges.
Even if an orderly emptying of bulk material from the mixing container can be ensured with these measures and in particular also bulk material which tends to form mixing material bridges, the associated, unavoidable development of noise is considered as disadvantageous. The noise level when using such a vibration motor or knocking generator is significant.
Starting from this discussed prior art, the invention therefore has the problem of constructing a mixing container of the initially cited type in such a manner that it can be emptied without an appreciable additional development of noise in an orderly manner even if filled with mixing material which tends to form mixing material bridges.
The foregoing example of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.